In alternators and generators used, for example, in automotive applications, it is common to provide a stud which extends out of the casing of the alternator or generator and which is employed to couple a wiring harness of the vehicle to the alternator or generator circuit board. The stud is typically threaded at both ends, one of which ends is bolted to the circuit board, while the other end receives a bolt or nut used in securing an eyelet terminal of a harness wire to the stud. In order to facilitate attachment of the stud to the circuit board, the portion intermediate its two threaded ends has a hexagonal shape for engagement by a wrench or spanner. The hexagonal portion includes a shoulder which acts as a stop to limit the travel of the harness bolt on the stud.
It has been found that with this type of stud, it is possible for the harness bolt to be over-torqued during tightening and untightening, leading to possible damage to the circuit board and/or to the possibility of unscrewing the stud from the circuit board on attempted removal of the harness bolt.
The present invention seeks to overcome this problem.
An electrical terminal in accordance with the present invention comprises a washer including a substantially flat contact wall with an aperture therethrough and at least two wall portions depending from the contact wall, each wall portion having an inwardly directed engagement surface lying on an arc of predetermined circumferentially length; and a stud including a connection end adapted to extend through the aperture, and a polygonal tightening portion receivable between the wall portions and comprising a plurality of substantially identical flat surfaces of predetermined length, the length of each flat surface being less than the length of each engagement surface, and the engagement surfaces resiliently engaging the polygonal tightening portion.
The shape of the washer ensures that it can rotate on the stud, thereby providing protection against over-torquing of a harness bolt. Moreover, the engagement of the surfaces acts to retain the washer on the stud, thereby facilitating assembly of the generator or alternator.
Preferably, the polygonal portion of the stud is substantially hexagonal. This shape matches conventional spanners and wrenches.
According to another aspect of the present invention, there is provided an electrical terminal washer for an electrical terminal as herein described.